[blimp] Add SkPicture caching support.

blimp/engine/renderer/engine_image_serialization_processor.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BLIMP_ENGINE_RENDERER_ENGINE_IMAGE_SERIALIZATION_PROCESSOR_H_
 #define BLIMP_ENGINE_RENDERER_ENGINE_IMAGE_SERIALIZATION_PROCESSOR_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "blimp/common/blimp_common_export.h"
 #include "blimp/engine/mojo/blob_channel.mojom.h"
 #include "cc/proto/image_serialization_processor.h"
-#include "third_party/skia/include/core/SkPicture.h"
+#include "cc/proto/picture_cache.h"
 
 class SkPixelSerializer;
 
 namespace content {
 class RenderFrame;
 }  // class content
 
 namespace blimp {
 namespace engine {
 
-// EngineImageSerializationProcessor provides functionality to serialize and
-// deserialize Skia images.
+// EngineImageSerializationProcessor provides functionality to serialize
+// and temporarily cache Skia images.
 class BLIMP_COMMON_EXPORT EngineImageSerializationProcessor
     : public cc::ImageSerializationProcessor {
  public:
   explicit EngineImageSerializationProcessor(
       mojom::BlobChannelPtr blob_channel);
   ~EngineImageSerializationProcessor();
 
   // cc::ImageSerializationProcessor implementation.
-  SkPixelSerializer* GetPixelSerializer() override;
-  SkPicture::InstallPixelRefProc GetPixelDeserializer() override;
+  std::unique_ptr<cc::EnginePictureCache> CreateEnginePictureCache() override;
+  std::unique_ptr<cc::ClientPictureCache> CreateClientPictureCache() override;
 
  private:
+  // A serializer that be used to pass in to SkPicture::serialize(...) for
+  // serializing the SkPicture to a stream.
   std::unique_ptr<SkPixelSerializer> pixel_serializer_;
+
   mojom::BlobChannelPtr blob_channel_;
 
   DISALLOW_COPY_AND_ASSIGN(EngineImageSerializationProcessor);
 };
 
 }  // namespace engine
 }  // namespace blimp
 
 #endif  // BLIMP_ENGINE_RENDERER_ENGINE_IMAGE_SERIALIZATION_PROCESSOR_H_